42 NONAGRIA GEMINIPUNCTA. 



NoNAGRIA GEMINIPUNCTA. 



Plate LXI, fig. 2. 



I am happy to acknowledge my obligation to Mr. 

 Howard Vaughan for my acquaintance with this 

 fen-haunting species. I had hoped to obtain more 

 information about its earlier stages, but after waiting 

 since 1870 I have thought it best to publish what I 

 know, so few fen collectors seeming to care about 

 larvae. 



Two pieces of Arundo phragmites were sent to me 

 on June 21st by Mr. Vaughan, each containing a larva 

 of this species. The reeds appeared to have been cut 

 rather low down towards the base, as they were not 

 green and bore no fresh leaf, but were of a pale buff 

 tint, somewhat like cane in texture, though on some 

 parts there were remains of old dried leaf cuticle of a 

 whity-brown or pale brownish-grey tint; the pieces 

 had been cut with a knot left at either end ; the length 

 between the knots inhabited by a larva measured 

 about four and three-eighths to four and a half inches, 

 the diameter three-eighths of an inch ; the sign of a 

 tenant consisted of two orifices plugged from within ; 

 the upper hole by which the imago escaped was five- 

 sixteenths of an inch from the knot, and the oblong 

 hole itself a quarter of an inch in length in a perpen- 

 dicular direction, and its breadth a little more than 

 one-eighth of an inch, spun over with grey silk, be- 

 hind which were particles of pith adhering;* the 

 lower hole was not quite in a line with that above, 

 though both holes could be seen at once ; its distance 

 from the lower knot half an inch, its length nearly a 

 quarter of an inch ; the outline of the orifice was 

 oblique and irregular, it being, in fact, composed of 



* Mr. Vaughan's impression is that the larva of geminipuncta does 

 not quite cut through the reed stem, but leaves a thin film of the 

 cuticle over the upper orifice as a protection, which sometimes, from a 

 cause unknown, is wanting. — W. B. 



